Labour were thrashed in 1983, but they retained some strength in their heartlands — the north, the West Midlands, parts of London, south Wales and Scotland.

In 2017, it seems every part of the UK previously loyal to Labour will turn against them. It’s going to be a painful campaign.

Labour’s already been routed in Scotland, but to see the Conservatives become the opposition to the SNP will be especially galling. That won’t in itself worsen the party’s position at Westminster, but a collapse in support in Wales definitely will.

The warning signs were obvious last year. UKIP made gains in the Welsh Assembly, then a month later Wales backed Brexit. Now it seems UKIP support has been a gateway for voters to switch to the Conservatives, previously a toxic brand across much of Wales.

In January, one-third of Leave voters told pollsters they’d vote Conservative in future. Now two-thirds say they’ll back the Tories.

It could see places like Bridgend, Wrexham and Newport lost to Labour. The Lib Dems hope to pick up at least one seat in Cardiff.

Labour’s Scottish leaders have worked hard to distance themselves from Jeremy Corbyn — but it’s not clear their Welsh leadership has done the same.

This election campaign will take Tory campaigners into places they wouldn’t normally risk. The campaign has a long way to go, and if we’ve learned anything in the last two years it’s to expect surprises. But right now, it seems there’s nothing Labour can do to stop the rot in the places they used to feel safest…